docs: align heartbeat defaults note

Co-authored-by: fatedier <7346661+fatedier@users.noreply.github.com>

conf/frpc_full_example.toml

@@ -133,8 +133,10 @@ transport.tls.enable = true
 # transport.tls.disableCustomTLSFirstByte = true
 
 # Heartbeat configure, it's not recommended to modify the default value.
-# The default value of heartbeatInterval is 10 and heartbeatTimeout is 90. Set negative value
-# to disable it.
+# If tcpMux is enabled (default), heartbeat is disabled and tcp mux keepalive
+# interval controls the liveness detection instead.
+# When tcpMux is disabled, the defaults are heartbeatInterval = 30 and heartbeatTimeout = 90.
+# Set negative value to disable it.
 # transport.heartbeatInterval = 30
 # transport.heartbeatTimeout = 90
 

conf/frps_full_example.toml

@@ -22,7 +22,9 @@ kcpBindPort = 7000
 # transport.quic.maxIdleTimeout = 30
 # transport.quic.maxIncomingStreams = 100000
 
-# Heartbeat configure, it's not recommended to modify the default value
+# Heartbeat configure, it's not recommended to modify the default value.
+# If tcpMux is enabled (default), heartbeat is disabled and tcp mux keepalive
+# interval controls the liveness detection instead.
 # The default value of heartbeatTimeout is 90. Set negative value to disable it.
 # transport.heartbeatTimeout = 90
 

pkg/config/v1/client.go

@@ -133,6 +133,8 @@ type ClientTransportConfig struct {
 	// HeartBeatTimeout specifies the maximum allowed heartbeat response delay
 	// before the connection is terminated, in seconds. It is not recommended
 	// to change this value. By default, this value is 90. Set negative value to disable it.
+	// Note: When TCPMux is enabled (default), heartbeat checks are disabled and
+	// the TCP mux keepalive interval controls liveness instead.
 	HeartbeatTimeout int64 `json:"heartbeatTimeout,omitempty"`
 	// TLS specifies TLS settings for the connection to the server.
 	TLS TLSClientConfig `json:"tls,omitempty"`

pkg/config/v1/server.go

@@ -172,6 +172,8 @@ type ServerTransportConfig struct {
 	// HeartBeatTimeout specifies the maximum time to wait for a heartbeat
 	// before terminating the connection. It is not recommended to change this
 	// value. By default, this value is 90. Set negative value to disable it.
+	// Note: When TCPMux is enabled (default), heartbeat checks are disabled and
+	// the TCP mux keepalive interval controls liveness instead.
 	HeartbeatTimeout int64 `json:"heartbeatTimeout,omitempty"`
 	// QUIC options.
 	QUIC QUICOptions `json:"quic,omitempty"`